Hello. I am replacing part of my backyard lawn. i have removed the top layer of old sod which has mostly dandelions and clover. do I have to get rid of it completely before putting new sod or I can just turn the old sod so it is faced soil up and apply a layer of top soil before putting new sod. I was trying to remove as much soil as possible from the chunks of old sod but it is very hard. My soil is mostly clay so it doesn’t come off easily and I am trying to save time as well. your answer is very much appreciated. I live in Richmond Hill.
Thank you for contacting the Toronto Master Gardeners.
Placing sod upside down at the bottom of a planting bed is an ecological and savvy way to reuse old sod. However in order to smother and kill the weeds in the old sod properly, it should be topped with 6-10 layers of newsprint and a substantial volume of organic matter and top soil. If the sod is covered only with a layer of topsoil and new sod, then there is a chance that the dandelions and clover that you worked so hard to get rid of will grow back, even when the old sod was placed upside down.
One way to get around this is to make sure that all plant materials in the old sod are dead before you put it back into the lawn. Exposing the excavated sod under the sun for a few weeks, away from any moisture, should do the trick. Or you can kill the weeds in situ by solarization, which takes about 4-6 weeks in the summer heat.
We hope this will help you in deciding on how to deal with your old sod. Good luck with a new, weed-free lawn!